This invention relates in general to submersible pumps, and in particular to a method and apparatus for locking the impellers of a centrifugal pump within the diffusers.
One type of submersible pump is a centrifugal type that has a tubular housing. A shaft driven by a submersible motor extends through the housing. Stages of diffusers are mounted in the housing stationarily. An impeller is carried inside each diffuser for rotation with the shaft. The rotating motion of the impeller imparts a rotating motion to the liquid, causing it to pass through the diffuser stages with successively increased pressure.
During assembly of the pump, diffusers and impellers are alternately placed over the shaft, then this assembly is placed inside the housing. Prior to placing the assembly in the housing, the impellers must be located relative to the diffusers. In one method, a locking ring or spring provides a specified locking force to hold the impellers to the shaft. Using this method, all parts must be precisely machined. In another method, shims are placed between the impellers. This method is slow and tedious because of the different dimensions.